Menstrual tampons for intra-vaginal use have long been in use and are favoured by many women as they are considered to be hygienic, non-obtrusive and comfortable to wear, lacking the occluding plastic backing of external protection devices such as sanitary napkins. A further advantage is that tampons are discrete and can be used with swimwear and other tight-fitting garments without being visible from the outside.
Tampons are commonly made from absorbent fibres, usually cellulosic fibres such as cotton fibres or regenerated cellulose fibres, such as viscose. It is also known to include other absorbent materials such as absorbent foams and superabsorbent gelling materials in tampons and also non-absorbent materials such as non-absorbent fibres, binders and fillers.
In order to better utilise the absorption material it has been suggested to provide tampons with external grooves or channels in order to increase the surface of the tampon that will be available for absorption. These grooves or channels may be formed by compression of the tampon body and may be arranged in a spiral configuration or may run as straight from the top of the tampon to the withdrawal end as described in WO 2002/078586, WO 2002/076357, WO 95/03766 and WO 2004/028428. However, it has been found that even when provided with such grooves or channels, users still experience a problem with fluid leaking out past the tampon. Such leakage often occurs prematurely, before the tampon has been fully saturated with liquid.
WO 2008/062322 A2 discloses a sanitary tampon that has been impregnated with a hydrophobic substance in order to counteract expansion and absorption in the treated end zone of the tampon. The hydrophobic substance is said to limit leakage and facilitating withdrawal of the tampon after it has been used. However, for several reasons it is highly desirable to avoid any additives to a tampon as any substance that will be in contact with the mucosal tissues may potentially cause problems with irritation and allergy. Additional components in a disposable article such as a tampon will also increase the production cost both by complicating the production process and by adding to the material cost. Moreover, the hydrophobic substance will negatively affect the absorbent capacity of the tampon by blocking the capillary structure in the tampon and by limiting the expansion capacity of the tampon.
Accordingly, it is an object of the present invention to provide a menstrual tampon having improved ability to prevent premature leakage.